脉冲加热惰气熔融–热导法测定不锈钢冶金粉末中氮含量
Determination of Nitrogen Content in Stainless Steel Metallurgical Powder by Pulse Heating Inert Gas Melting and Thermal Conductivity Method

对脉冲加热惰气熔融-热导法测定不锈钢冶金粉末中氮含量的方法进行优化，试样在110℃干燥箱中干燥1 h，脱气周期2次，脱气功率5.7 kW，燃烧功率为5.2 kW，氮分析时间55 s，样品称样量为0.2 g~0.5 g，锡囊做包裹容器、镍囊做助熔剂，室内空气湿度 < 70%条件下，样品中的氮释放完全，无拖尾现象，可以获得最佳结果。同时校准曲线标准物质与试样均采用锡囊包裹容器、镍囊做助熔剂，可以消除影响。方法的检出限为0.0000408%，检出下限为0.000136%。分别对3种不同含量试样进行精密度试验，测定结果的相对标准偏差(n = 6)为0.32%~0.75%，方法回收率在95.7~105.6之间，方法准确、快速，可用于不锈钢冶金粉末中氮含量的快速测定。
The method of determination of nitrogen content in stainless steel metallurgical powder by pulse heating inert gas melting and thermal conductivity was optimized. The sample was dried in a drying oven at 110？C for 1 h, the degassing cycle was 2 times, the degassing power was 5.7 kW, the combustion power was 5.2 kW, the nitrogen analysis time was 55 s, the sample weight was 0.2 g~0.5 g, the tin bag was used as the wrapping container, and the nickel bag was used as the flux. Under the condition of indoor air humidity < 70%, the nitrogen release in the sample is complete and there is no trailing phenomenon, so the best results can be obtained. At the same time, the standard material of calibration curve and the sample are both coated with tin capsule and nickel capsule as flux, which can eliminate the influence. The detection limit of the method was 0.0000408% and the detection limit was 0.000136%. The relative standard deviation (n = 6) of the measured results was 0.32%~0.75%, and the recovery rate was 95.7~105.6. The method is accurate and rapid, and can be used for the rapid determination of nitrogen content in stainless steel metallurgy powder.